The present invention relates generally to fluid servo systems and, more particularly, to fault detectors for redundant hydraulic servo systems.
Fluid controls, such as servo systems are used for many purposes, one being, for example, to position flight control surfaces of an aircraft. In such an application redundant servo systems, including plural similar servo actuators, for example of the electro hydraulic type, may be employed to assure proper position control of the output device in case of a failure of one of such servo actuators, thus increasing the mechanical reliability of the aircraft. Such plural redundant servo actuators may be operated on a continuous simultaneous basis or on an alternate basis, with conventional electronic controls being available to select the operating mode and to control energization, normal operation and shut down of the respective servo actuators.
The health or condition of the electrical and hydraulic portions of a multiple channel servo actuator should be assessed on a continuous basis. Various types of electronic monitors are available to monitor such electrical portions. The present invention, though, is directed to the detection of faults in the hydraulics or other operating fluids of a servo system, more particularly, of a redundant servo system.